A question from abroad (not England). “...likely that they’ll ruin tonight’s game with their theatrics, moaning, diving, arguing with the ref, Xavi thinking he is the ref, and all round general cheating? They have been known to resort to that in past Champions Leagues as soon as they realise they’re in a contest, or are they better behaved under the new manager than they were under the previous two?”..I read quite a lot observations like these on the Guardian website. Why is that, do you think? I read Dutch papers, German papers and American papers but only the English fans seem to think that Barça are a bunch of stealing and cheating players. Could this be some kind of envy?

I think there is an English element to that, yes .... more sensitivity to certain types of cheating in certain places ... in England there are less moans about hard nut defenders kicking the crap out of players ... in Spain less about dives.

Has there been any revolt amongst Barcelona fans in the city to the continued commercialisation and increase in sponsorship particularly on the jesery? Or do the fans view this as necessary in the modern game to complete with the likes of Man City for players such as Neymar?

Loved the book (no thanks required for the plug). It was great to see Puyol back in the heart of the defence for the Rayo game at the weekend, is there any chance of Barça signing some decent defenders any time soon or are Bartra and Montoya rated that highly?

Hi Sid (from a Madrid bookshop you know well), although many here will be claiming this match will produce a potential trophy winner, isn’t it the case that German clubs (in particular Bayern Munich) are the ones who will need knocking off their perch? Or do you think that Barça (or Manchester City) will stand a better chance of competing against Bayern this year. Always assuming the Arse don’t do it first...

Well, I do feel like Bayern are the clear favourites, yes. Much will depend on draws etc ... some teams are pretty much in the quarters already for example and another favourable draw and, hey presto, semi-finalists. I 'm starting to see RM as the next strongest side after Bayern.

Isn’t the comparison of Man City to Barça a little, well, nuts - A team who’ve won one league title by the skin of their teeth, never got out of the CL group stage before and lost last year’s FA Cup final to a bottom three team, and led by a manager whose medal collection wouldn’t trouble a teaspoon’s worth of metal polish. Isn’t this just hubris and arrogance that would make Mourinho blush? One team in Manchester? Let’s see which one that make it to the quarter-finals, shall we!

I'm not sure anyone is making the comparison on those grounds .... it's more that there are clearly some points of coincidence in terms of ideas, aims and objectives ... embodied, of course, in Txiki B and Soriano.

"One team in Manchester" strikes me as a very strange and uncharacteristic thing to say ... did he really say that? And like that?

Do you think Pellegrini will bring in Javi Garcia, a Real Madrid academy product to add grit and a bit of fire to the City midfield to counter the superlative Barcelona midfield - This is considering the tendency of Silva, Fernandinho and Toure Yaya to slip up on their defensive duties.

Much has been made of City having to change a 4-4-2 shape that Pellegrini has adhered to regardless of results or opposition. Whether or not this leaves us short numbered in midfield, how often do Barcelona come up against this system, against who and how do they seek to address this?

Pellegrini's 4-4-2 in Spain was always a very narrow one that actually brought more bodies into midfield. Almost a 4-2-2-2. As I understand it, (although I don't see enough of City), there's a small element of that at City ... except with Navas, of coure.

Few teams play 4-4-2. Atletico do but they actually drew one of the forwards into midfield tto fill the space and the two 'wide' men were narrow.

I was listening to the Spanish Football Podcast yesterday, which I think is excellent and worthy of a plug (especially if it gets me a response), and heard you describe Xavi as the best Spanish footballer in history. I just wanted to ask why you would choose Xavi over Iniesta, because I’ve always thought Xavi was more important to the system but it would never of reached the level it did without Iniesta.

The top three in the Champions League (and all but Atletico still in some domestic cup if I’m not mistaken) - This infighting clearly favours Bayern, who already have a gap in the lead of the Bundesliga - The side that go out of this tie might even consider it a relief

They're scoring goals from set plays ... the early diagonal ball has occasionally been useful ... I don't see this style as a clean break from the past. I think that has been partly exaggerated, but there are some elements of being a tad more direct that are interesting. Still some of flaws are there at the back: central defence and Alba and/or Alves

I'm not sure City will be quite that open, but yes Pedro may well be the player best equipped to exploit those spaces. I imagine what happened against Chelsea may mean that Pellegrini leans against leaving only two men in the middle.

Martino mentioned the constant use of rotation this season in order to avoid a repeat of last year where they came up short against Bayern. Do you think the gulf in class was due to, a large extent, this tiredness or do you think Barça just cannot match them at the moment, regardless?

I think Barcelona faced a team that was better than them anyway, to be honest ... but their physical condition was definitely a factor. Messi was not the only one injured and many were running on empty. martino suggested the other day that rotations may come to an end now as season hits key moments ... that's going to be very interesting, as we're still not sure yet what his perfect XI is (if all players fit).

Barça have always been very proactive in regenerating their teams. Do you think that they are making the mistake of keeping their players from the great era for a little too long? Xavi and Dani Alves surely are past their best years. Especially Dani Alves who does not offer much in defence and is often static in attack, contributing very little other than keeping the ball. Mascherano? Are they untouchable at Barça?

Would failure to beat Manchester City over the two legs put doubts to Martino lasting past the summer? Yes he is joint top of La Liga, but this isn’t seen as anything but a mandatory requirement for Barcelona. I just feel having seen some of the comments from players and the media Martino may not have a secure a grip of his position as he would like.

What with Barça and Messi’s recent record in this country being a shit one, do you think this only makes it all the more likely that they’ll ruin tonight’s game with their theatrics, moaning, diving, arguing with the ref, Xavi thinking he is the ref, and all round general cheating? They have been known to resort to that in past Champions Leagues as soon as they realise they’re in a contest, or are they better behaved under the new manager than they were under the previous two?

I don't think Messi's record is a shit one, but it may be a bit shitter than his record against other teams in other countries ... I'm also not convinced that Barcelona are significantly more cheaty than other teams,

More consistent opportunities, a slightly more direct style, a better sense of being "valued", more often in a deeper position with more involvement (less often the false 9, although he has played there a bit too)

Where teams tend to go wrong against Barça is that they tend to concentrate so much on stopping Messi than actually playing against Barça as a team. Many managers double up on the Argentinian freeing up the likes of players such as Iniesta and Sanchez. I hope Pellegrini doesn’t have Fernandinho chasing him around all night leaving Yaya over-ran in the middle of the park. Im still going for a score draw, thoughts?

What do you make of Bartomeu so far? ( I know it’s not long!) He seems to be reaching out ( to Cruyff for example). Can he put the mal rollo in the “entorno” to rest for a while? How big a tie is this as regards Bartomeu’s reign as president? Cheers!

Hi Sid. Good article about the City “blueprint”. Any truth in the rumour that Isco might be coming to City after all this summer? I’m a bit sceptical, as £30m sounds like more than we were rumoured to have bid last summer. And kind of related, how about Valdes?

Is there a case to be made for Martino repeating some of his tactics that worked well in the clasico? Playing Messi on the right could potentially neutralise the attacking threats of Kolorov and Silva, as well as exploit their defensive weakness. And following the Guardiola blueprint, would it be prudent to play both Song and Busquets, with Xavi just ahead of them and Iniesta on the wing? This would leave Fabregas in the False 9 position. Surely conservatism and pragmatism are the name of the game away from home, with Martino being more than willing to do what’s best for a specific game?

Good question. I have some doubts but it depends how you want to play and where your priorities lie. Certainly, Barcelona need to think about how they approach a post-Xavi future. He has been the ideologue for so long. And Cesc has played very well ... less control than Xavi but maybe more decisive. Tonight I would imagine all of them play: Bus, Iniesta, Xa and Cesc

The build up to this game reminds me of the 2009 quarter-final against Arsenal; everyone looking for the positive aspects in the English team and pointing out the weaknesses in Barcelona after the 2-2 draw at home. Barcelona went on to blow them away 4-1, with Messi ripping them apart. Is this sort of build-up playing into Barcelona’s hands? I can see them all training that little bit harder this week, with a real pep in their step looking forward to the challenge rather than the (albeit exciting) slog in the league.

I think the search for weaknesses in a team (in this case Barcelona) is usually based on a recognition that they are very good, and therefore an implicit suggestion that they are favourites ... a kind of "don't panic, all is not lost" attitude. Barcelona, certainly (and RM by the way) are very well aware that City are the hardest team they could have got. Many group winners got ties where they are extremely clear favourites: RM, Chelsea, etc

Depends what you mean by 'handle' ... will they compete for territory, possession, or incisiveness? Will they be happy for Barcelona to have the ball or will they want it back and quickly? that's going to be very interesting to see.

Hi Sid. The return of Kompany has helped City’s backline. However, their defence is still vulnerable if you exclude Zabaleta and Kompany. The same defensive problems plague Barcelona. Do you see the shift to a more attacking approach – and the resultant loss in defensive composure – from the top European sides as a by-product of this midfield-heavy mentality, with central defenders being asked to play further up the pitch, while the full-backs are asked to push up and support the wingers?

I think the midfield focs does not necessarily come at a cost of defensive stability but rather as the search for that defensive stability. Barcelona look vulnerable at the back and they are of course, but the stats show that they concede fewer than others ... precisely (in part at least) as a product of that midfield-driven style.